How does a translator work?

I was interested in one question: how is a translator arranged in which there are several languages. (like Google) For example, it’s clear when the English-Russian, German-Russian, French-Russian, there are English, German, French analogues for every Russian word. Those. attached to the Russian word.
And when the translator from each to each, it is not clear what is attached. Maybe they came up with some kind of language to which other languages ​​are tied.
Somebody knows?